Frank Dresser wrote:


"craigm" wrote in message
...


Mike,

You should be quoting Frank, not me. Look closer at my post. I posted
links
that indicate what Frank wrote my be wrong. Read the material in the
links and decide for yourself.

(You would need a pile of cash to buy enough fittings, anyway. )


craigm

I don't see any contridiction between the sites and what I said. Even if
the ohmmeter is a DC instrument, the hypothetical infinately long
transmission line would see only DC pulses. The pulses might last a few
seconds or untill the battery dies or untill the operator meets his
eternal
reward or until the whole universe shuts down. I don't see how it
matters. None of these pulses would get into the troublesome "low
frequency" area of the transmission line analysis.

Hey, I could be wrong. But, if so, how am I wrong? What do you think
would happen if you hooked up a DC ohmmeter to an infinately long
transmission line?

Frank Dresser


In this discussion you can't arbitrarily separate AC and DC components. The
DC pulses you speak of are a summation of a DC term plus AC components
based up on the repetition and duration of the pulses. Assuming that these
are slow pulses from connecting and disconnection the meter, there would be
significant low frequency content.

Hooking up a DC voltmeter to an infinitely long line is something that
requires you to look at the transient response of the system as opposed to
what would normally be viewed in a steady state manner.

Since the papers I referenced show the low frequency behavior looking
capacitive, I would expect the ohmmeter readings to look similar to one
trying to measure a capacitor.

craigm